In the snap, Biermann, 18, captions the diagonal image with a simple, "happy new years," and a winking emoji. The picture, which features her lips prominently, would make Kylie Jenner proud. After all, the Don't Be Tardy star goes to the same doctor as Jenner for her Juvederm sessions.

In December, Biermann posted a mesmerizing high-speed video of her lips as Dr. Simon Ourian, the cosmetic dermatologist who, in addition to Jenner, also gave her mom "emergency" Botox, filled them up with the temporary product. "Thank you thank you thank you!!! to my favorite, @simonourianmd1 !!! my lips are my biggest insecurity and I'm so happy w my results now! you truly are the best! even though i hate needles you made this very easy," she wrote at the time. "thank you again."

Some critics fired back that Biermann was too young, but one doctor explains that may not be the case.

"Plastic surgery is an extremely powerful tool. It can allow for enormous benefits or alternatively cause massive destruction, physically and psychologically. Those looking to alter their appearance should exercise careful consideration before going under the knife," Dr. Payman Simoni, a double board certified facial plastics expert, tells Us Weekly exclusively.

However, Dr. Simoni is careful to distinguish lip injections from the catch-all phrase, "plastic surgery." Lip injections like Biermann's and Jenner's aren't permanent, and they're only a procedure, not a surgery. "Lip injections can be done at any age, but the most optimal age is when the individual has a mature brain capacity to understand the risks and the benefits of the lip injection," he says.

A post shared by Brielle (@briellebiermann) on Dec 28, 2015 at 3:35pm PST

Most of the concern stems from the idea that young people may not understand what they'll look like after getting fillers or a nose job. But it is clear that Biermann is happy with her results and even loves taking twinning selfies with her mom — who also admits to using fillers and Botox. "My twin @kimzolciakbiermann," Zolciak-Biermann's look-alike daughter captioned one video posted to Instagram.

A post shared by Brielle (@briellebiermann) on Jan 1, 2016 at 11:03am PST

But her lips and blonde hair aren't the only thing she shares with her mother. Biermann is also a big supporter of the same waist trainer as her mama. "yes! #waistraing with the #waistgangsociety @premadonna87 @waistgangsociety wow it's so comfy and my frame feels and looks amazing already," she wrote along with a front and side shot of her blue corset.